Cape Cod, the summer of 2003.
A shadowy figure known only as the Crimson Cape Killer (or C.C.K.) commits a series of tourist murders in the week leading up to the 4th of July. Bludgeoning his victims and dumping the bodies on the beaches for police to find. When the lead detective on the case and his wife are brutally murdered in a home break-in, the murders seem to stop, and the case eventually goes cold.

Cape Cod, the summer of 2023.
Twenty years later, a freak accident will set a local police officer on a collision course with the monster who took everything from him. With the help of his waitress sister, her medium girlfriend, and a true crime influencer with Cape roots, he will uncover the twisted secrets of the "Crimson Cape."